Place the apple sauce, water, sugar, and dried fruit in a saucepan. Bring to a boil and simmer for 20 minutes, then allow to cool. Set the oven at 300 deg F (cool). Line a 6-inch round cake tin with greaseproof paper. Mix the egg whites into the fruit mixture, then sift the flour and baking powder into it too. Mix, adding water if necessary to make a stiff batter. Pour into the prepared tin, sprinkle the top with brown sugar, and bake for 1 1/2 to 2 hours, until a skewer inserted into the centre of the cake comes out clean, more or less with all this fruit, it's not going to come out very clean anyway! The amount and type of fruit in this recipe can be varied very much to produce different results. Many folk in this country would use sultanas (yellow raisins) for some of the fruit, but I don't like them so I don't use them. You can substitute 1/2 cup of chopped glace cherries for some of the fruit, or add chopped candied orange peel, dates, apricots... The possibilities are endless.